1. Field of the Invention
The present invention relates to an ink jet recording apparatus and method using an aqueous ink and, more particularly, to an ink jet recording apparatus and method featuring improved multi-tone reproduction characteristics.
2. Description of the Prior Art
In ink jet recording apparatuses, such as ink jet printers, for the purpose of tone reproduction, a tone reproduction technique of binary value is in general practice such that a area tone method is employed with dot diameter size kept constant without any change. However, with such a reproduction method of binary value, it is difficult to carry out smooth tone reproduction free of reproduction irregularity with respect to various images, from solid image to highlight image, and to faithfully reproduce a middle color, such as human skin color, in full-color images such as photographic images.
For the purpose of improving tone reproduction of full-color images using such a reproduction technique of binary value, it is known to use ordinary four color inks (yellow ink, magenta ink, cyan ink, and black ink) and photo inks (cyan and magenta inks with low colorant concentration, and when required, black ink with low colorant concentration) in combination.
In such a method, however, heads corresponding to six or seven kinds of inks and cartridges for housing the inks are required, and this complicates the construction of the apparatus. Further, the increase in the kinds of inks to be used raises a problem such that when any one kind of the inks has been consumed, it is necessary to replace the cartridge of the consumed ink with a new cartridge, and this results in increased frequency of cartridge replacement at the user's end.